Pivoting ring seal

ABSTRACT

The instant invention provides for a pivoting ring that can be used as a seal for an inflatable member. The pivoting ring seal offers a mechanical action which acts to tighten with increasing inflation and/or expansion of an inflatable member. As the inflatable member increases in pressure and/or size, one side of the ring is lifted and pivots around a fulcrum in the middle of the ring seal causing the opposite side of the ring seal to decrease in diameter. The pivot ring causes the opposite part of the seal to tighten about an inner member allowing for a higher-pressure seal. In addition to a higher pressure seal, the working length of the inflatable member can be adjusted by moving the ring along the length of the inflatable member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit under 35 U.S.C. 119(e) ofU.S. Provisional Application No. 61/475,822 filed on Apr. 15, 2011 whichis incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

There are many medical procedures which employ balloon catheters. Inmost cases, the length of the balloon must be pre-determined by theclinician prior to selection and insertion of the balloon catheter intothe body. For example, in balloon angioplasty, the length of thediseased blood vessel is first determined. Usually, the physiciandetermines in advance the approximate size of the vessel area to betreated. This can be done, for example, through fluoroscopic X-ray,ultrasound imaging, and/or CAT scanning techniques. When balloon lengthchoices are few, a clinician will generally choose a length shorter thanthe length of the lesion to be treated and will sequentially dilatedifferent portions of the vessel. This extends the time and risks of theprocedure. Where several catheters of differing balloon lengths areavailable the physician will select a balloon length which will coverthe entire length of the portion of the vessel requiring dilatation. Iftwo or more blockage sites of different lengths exist within the sameartery and the physician determines that two or more different sizedballoons must be used, the physician will generally treat the mostproximal site first, deflate and withdraw the first balloon catheter,and then insert a second balloon catheter with a different lengthballoon to treat the second stenotic region. Shorter balloons are oftenused to dilate lesions located on sharp bends in coronary arteries toprevent straightening and possible damage during the dilatationprocedure. Longer balloons are employed to dilate large areas withextensive disease. Changing balloons, however, is a costly,time-consuming and potentially risky procedure that could lead to injuryor death of the patient.

In addition, while it is believed the primary use for balloon cathetersis for treating profuse disease in blood vessels, and in particulardiseased portions of peripheral and coronary arteries, there are certainother procedures where one of a plurality of catheters having differentlength balloons must be selected. For example, when utilizing a drugeluting balloon, it would be preferable to determine the area of thevessel where a drug is to be delivered and adjust the balloon lengthaccordingly. This will only release the drug in the targeted area andavoid exposing healthy portions of the vessel to the drug. Usually thesedrugs are toxic to healthy tissue so a targeted approach is desirable.

In addition, what has been needed and heretofore unavailable is a stentdelivery device, which allows for a variable length expandable memberneeded for proper stent deployment and safe and effective sizing of adeployed stent.

Thus, in the foregoing procedures, the physician must have catheterswith various sized balloons on hand so that he/she can select the propersize balloon when performing the procedure.

The instant invention obviates the need for having multiple lengthballoons in a stock room, allows for customizing the length of a balloonto the size of a lesion or stent and provides for targeted delivery of adrug utilizing a drug eluting balloon.

SUMMARY OF THE INVENTION

Compared to traditional balloon seals requiring adhesives and/or crimpedbands to prevent leakage or failure of an inflatable member, the ringseal of the invention (i.e. the ring of the invention, also sometimesreferred to herein as band(s), ring member(s) and pivot ring(s)) offersa mechanical action which acts to tighten the seal with increasinginflation and/or expansion. As the inflatable member increases in size,one side of the ring is lifted and pivots around a fulcrum between theends of the ring seal causing the opposite side of the ring seal todecrease in diameter and/or exert a compressive force. The pivoting (andthe reduction in diameter) causes the opposite part of the seal totighten about an inner member allowing for a higher-pressure seal. Inaddition to a higher pressure seal, the working length of the inflatablemember can be adjusted by moving the ring seal along the length of theinflatable member while it is not inflated.

Thus, one embodiment of the invention is directed to a medical devicecomprising an inflatable member wherein the working length of theinflatable member is adjustable in situ and/or by medical personnelbefore insertion into a body conduit. Significant benefits can resultfrom this unique adjustability, again whether through the ability ofclinicians to adjust the working length of an inflatable member in situduring a medical procedure, by adjusting the size of the inflatablemember prior to performing a medical procedure, or some combination ofthe two.

Another embodiment of the invention comprises a seal that increases itssealing force as pressure and size of an inflatable member increases.

Another embodiment of the invention comprises a medical devicecomprising an inflatable member having opposing ends, a smaller deflatedprofile and a larger inflated profile, a working length, and a ringmember having opposing ends, said ring member being slidable, whether insitu or prior to insertion of a device in the body, or some combination,to any position between the opposing ends of the deflated inflatablemember, wherein when one opposing end of said ring member increases indiameter, the other opposing end of said ring member decreases indiameter upon inflation of the inflatable member. In one embodiment, theinflatable member drives the increase in the diameter of the ring memberin one opposing end. In another embodiment, the decrease in diameter ofone opposing end of said ring member restricts inflation of a portion ofsaid inflatable member.

In another embodiment, said inflatable member is disposed over anelongate member. In another embodiment, said elongate member is acatheter or a guidewire. In another embodiment, the decrease in diameterof the opposing end of said ring member makes said end constrict aboutsaid inflatable member and/or said elongate member. In anotherembodiment, the constriction of the opposing end of said ring memberagainst said inflatable member and/or said elongate member results in aseal of at least one end of said inflatable member. In anotherembodiment, as the diameter of an opposing end of said ring memberdecreases, it further constricts against said inflatable member and/orsaid elongate member resulting in a tighter seal of at least one end ofsaid inflatable member. In another embodiment, the decrease in diameterof one of the opposing ends of said ring member restricts axial movementof said ring member. In another embodiment, said inflatable member is amedical balloon. In another embodiment, said medical balloon comprisesexpanded polytetrafluoroethylene (ePTFE). In another embodiment, theposition of said ring member adjusts the working length of said medicalballoon. In another embodiment, one method of adjusting the position ofthe ring member is by sliding the ring member along the axis of saidmedical balloon to the appropriate location in said inflatable member.In another embodiment, said medical balloon further comprises a ballooncover. In another embodiment, said balloon cover comprises ePTFE. Inanother embodiment, said medical balloon comprises a drug coating onsaid balloon and/or balloon cover. In another embodiment, said ringmember comprises a resilient metal. In another embodiment, saidresilient metal is nitinol. In another embodiment, the position of saidring member adjusts the working length of the expandable portion of saidinflatable member.

Another embodiment of the invention comprises a medical devicecomprising an inflatable member having opposing ends, a smaller deflatedprofile and a larger inflated profile, a working length, and a ringmember having opposing ends, wherein said ring member is positionedbetween the opposing ends of the said inflatable member and wherein anincrease in diameter on one of the opposing ends of said ring memberresults in a compressive force in the other opposing end of said ringmember. In one embodiment, said inflatable member drives the increase inthe diameter of said ring member in one opposing end. In anotherembodiment, said compressive force is caused by an increase in diameterof one of the opposing end of said ring member. In another embodiment,said compressive force of one of said opposing end of said ring memberrestricts axial movement of said ring member. In another embodiment,said compressive force of one of said opposing end of said ring memberrestricts inflation of a portion of said inflatable member. In anotherembodiment, said inflatable member is disposed over an elongate member.In another embodiment, said elongate member is a catheter or aguidewire. In another embodiment, said compressive force causes saidopposing end of said ring member to constrict against said inflatablemember and/or said elongate member. In another embodiment, as thediameter of said opposing end of said ring member decreases, it furtherconstricts against said inflatable member and/or said elongate memberresulting in a tighter seal of at least one end of said inflatablemember. In another embodiment, the inflatable member is a medicalballoon. In another embodiment, said medical balloon comprises ePTFE. Inanother embodiment, the position said ring member adjusts the workinglength of said medical balloon. In another embodiment, said medicalballoon further comprises a balloon cover. In another embodiment, saidballoon cover comprises ePTFE. In another embodiment, said medicalballoon comprises a drug coating on said balloon and/or balloon cover.In another embodiment, said ring member comprises a resilient metal. Inanother embodiment, said resilient metal is nitinol.

Another embodiment of the invention comprises a method of adjusting theworking length of an inflatable member comprising disposing at least onering member onto an inflatable member having a length, said ring memberconfigured to have opposing ends whereby when one opposing end of saidring member increases in diameter upon inflation of an inflatable memberthe other opposing end of said ring member decreases, and sliding the atleast one ring member to a predetermined position along the length ofsaid inflation member,. In one embodiment, increasing the diameter ofone of the opposing ends of said ring member results in a compressingforce in the other opposing end of said ring member. In anotherembodiment, said inflatable member drives the increase in the diameterof said one opposing end of said ring member. In another embodiment,there may be two or more ring members disposed on said inflatablemember. In another embodiment, the decrease in diameter of said oneopposing end of said ring member restricts inflation of a portion ofsaid inflatable member. In another embodiment, said inflatable member isdisposed over an elongate member. In another embodiment, said elongatemember is a catheter or a guidewire. In another embodiment, the decreasein diameter of the opposing end of said ring member makes said endconstrict against the inflatable member and the elongate member. Inanother embodiment, the constriction of the opposing end of said ringmember against said inflatable member and/or said elongate member resultin a seal of at least one end of said inflatable member. In anotherembodiment, as the diameter of the opposing end of said ring memberdecreases, it further constricts against said inflatable member and/orsaid elongate member resulting in a tighter seal of at least one end ofsaid inflatable member. In another embodiment, the decrease in diameterof one of said opposing end of said ring member restricts axial movementof said ring member. In another embodiment, said inflatable member is amedical balloon. In another embodiment, said medical balloon comprisesePTFE. In another embodiment, said medical balloon further comprises aballoon cover. In another embodiment, said balloon cover comprisesePTFE. In another embodiment, said medical balloon comprises a drugcoating on said balloon and/or balloon cover. In another embodiment,said ring member comprises a resilient metal. In another embodiment,said resilient metal is nitinol.

Another embodiment of the invention comprises a method of introducing acustomizable stent into a body conduit comprising, providing acustomizable stent and a medical balloon having opposing ends, a smallerdeflated profile and a larger inflated profile, and a working length,adjusting said customizable stent to a predetermined length, adjustingsaid working length of said medical balloon by disposing and sliding atleast one ring member between said opposing ends of said medicalballoon, wherein said ring member comprises opposing ends and anincrease in diameter on one of the opposing ends of said ring memberresults in a compressing force in the other opposing end of said ringmember, disposing said stent onto the working length of the medicalballoon, and inserting said medical balloon, at least one ring memberand stent into a body conduit. In one embodiment, said medical balloonand said stent are delivered to a predetermined site within said bodyconduit and said working length of said medical balloon is expandedthereby delivering said stent disposed on said balloon. In anotherembodiment, said customizable stent comprises stent rings interconnectedby polymer webs. In another embodiment, said customizable stent iscustomized by cutting said polymer webs interconnecting said stent ringsand removing said stent rings. In another embodiment, said methodcomprises using two ring members and sliding said ring members to adjustthe working length of said medical balloon. In another embodiment, saidmedical balloon is disposed over an elongate member. In anotherembodiment, said elongate member is a catheter. In another embodiment,said medical balloon comprises ePTFE. In another embodiment, saidmedical balloon further comprises a balloon cover. In anotherembodiment, said balloon cover comprises ePTFE. In another embodiment,said medical balloon comprises a drug coating on said balloon and/orballoon cover. In another embodiment, said ring member comprises aresilient metal. In another embodiment, a suitable resilient metal isnitinol.

Another embodiment of the invention comprises a pivoting ring thatcomprises a first end and second end, wherein when the first endincreases in diameter the second end decreases in diameter. In oneembodiment, said ring comprises a resilient material. In anotherembodiment, said resilient material is selected from the groupconsisting of a metal and polymer. In another embodiment, said metal isnitinol.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary embodiments of the present invention will be described inconjunction with the accompanying drawings. The accompanying drawingsare included to provide a further understanding of the invention and areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and together with the description serve toexplain the principles of the invention.

FIGS. 1A and 1B depict a “closed” ring of the invention. FIG. 1A depictsa side view of the closed ring and FIG. 1B depicts the end view of theclosed ring.

FIGS. 1C and 1D depict an “open” ring of the invention. FIG. 1C depictsa side view of an open ring and FIG. 1D depicts the end view of the openring.

FIGS. 2A and 2B depict one use of the ring of the invention placed overa balloon catheter. FIGS. 2A and 2B depicted the balloon catheter withthe non-inflated balloon and the ring of the invention placed over theballoon.

FIG. 2C depicts an expanded balloon with the ring of the invention in anopen configuration.

FIGS. 2D and 2E depict alternative embodiments of the invention,including having multiple rings of the invention on a balloon catheter.

FIGS. 3A and 3B depict a cross-section of a high-pressure balloonmounted on a single lumen catheter before (3A) and after (3B) inflationof said balloon.

FIGS. 4A, 4B and 4C depict a side view and an end view (4C) of a balloonwith two pivot rings which help refold a balloon after inflation.

FIGS. 5A and 5B depict a flattened cut pattern of a pivot ring of theinvention (5A) and said ring as cut (5B).

FIGS. 6A through 6D depict a balloon catheter and a pivot ring of theinvention between two fixed seals. The position of the pivot ring of theinvention is shown controlling the final working length of the inflatedballoon.

FIG. 7 demonstrates how the clamped pivot ring of the invention createsa seal and resists axial migration during inflation of a balloon.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Compared to traditional seals requiring adhesives and/or crimped bandsto prevent failure of an inflatable member, the pivot ring seal of theinvention (i.e. the ring of the invention) offers a mechanical actionwhich acts to tighten the seal with increasing expansion and/orinflation (which results in an increase in pressure). As the inflatablemember increases in pressure and/or size, one side of the ring is liftedand pivots the opposite side of the ring seal around a fulcrum betweenthe ends of the ring seal. The pivoting causes the opposite part of theseal to tighten about an inner member allowing for a higher-pressureseal. In addition to a higher-pressure seal, the working length of theinflatable member can be adjusted by moving the ring seal along thelength of the inflatable member prior to inflation and/or afterinflation and deflation. As used herein the term “working length” is thelength of the straight body section of an inflatable member afterinflation of said inflatable member.

Reference will now be made in detail to embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings.

FIGS. 1A and 1B depict a “closed” ring member 100 and FIGS. 1C and 1Ddepict an “open” ring member 100 (i.e. wherein fingers 112 are spreadopen). FIG. 1A is a side view of closed ring member 100 and FIG. 1B isan end view of the closed ring member 100. FIG. 1C is a side view ofopen ring member 100 and FIG. 1D is an end view of the open ring member100.

As shown in FIGS. 1A through 1D, one embodiment of the inventioncomprises a pivoting ring member 100 that comprises a first end 102 andsecond end 104. Ring member 100 also comprises a length, as depicted asarrow 106, and a lumen 108 therethrough (FIG. 1B). When ring member 100is closed, lumen 108 has a diameter that is, more or less, constantthrough length 106 of ring member 100. As illustrated by arrows 124 and126, diameter 124 of first end 102 has the same diameter 126 of secondend 104. Lumen 108 allows ring member 100 to be placed over aninflatable member or any other object. Ring member 100 further comprisesa plurality of slits 110 and fingers 112 near first end 102. Slits 110are cut through the thickness of ring member 100 and are made partiallydown length 106 of ring member 100 (which may or may not have gapsbetween the slits). In between slits are fingers 112 that spread apartas first end 102 increases in diameter, as described below.

Ring member 100 also comprises slots 116 and ring members 118 nearsecond end 104. Slots 116 are cut out of ring member 100 creating gaps120 around the circumference of second end 104. These gaps will decreasein size as second end 104 decreases in diameter and first end 102increases in diameter. Slots 116 allow ring members 118 to cometogether, thus allowing the reduction in diameter 126 of second end 104.In one embodiment, slots 116 are offset (staggered) from slits 110. Inanother embodiment, slots 116 and slits 110 overlap in pivot region 114.It has been discovered that offsetting the slots on either end of theband and then overlapping the slits allow the ring of the invention tohave a pivoting effect. This allows the ring member 100 to pivot inregion 114. Thus, as first end 102 increases in diameter 124 and secondend 104 decreases in diameter 126, pivot region 114 creates a fulcrum,allowing ring member 100 to pivot. Another embodiment of the inventioncomprises a pivoting ring that comprises a first end and second endwherein when the first end increases in diameter the second enddecreases in diameter. In another embodiment, the decrease in diametergenerates an inward force.

As stated above, pivoting ring member 100 comprises a first end 102 andsecond end 104 wherein when first end 102 increases in diameter thesecond end 104 decreases in diameter. This is illustrated in FIGS. 1Cand 1D. When ring member 100 is in the open configuration, fingers 112spread apart increasing the first end 102 diameter 124 and decreasingsecond end diameter 126. In one embodiment, a radial force pushesfingers 112 outwardly and causes the increase in diameter of first end102. One example of a radial force that spread fingers 112 apart is byplacing ring member 100 over an inflatable member and inflating saidmember. In another embodiment, the radial force is from a tube thatincreases in diameter, forcing fingers 112 outwardly.

In another embodiment, a final (smaller) diameter 126 can bepredetermined and be “locked” to a final diameter via mechanicalinterference. The “lock” on diameter 126 of second end 104 means thatforces (e.g. balloon pressure) on first end 102 will not allow secondend 104 of the band to compress together any further once it is in itspredetermined diameter due to ring members 118 touching each other, thuslocking diameter 126 of said second end 104. The reduction in diametercan be tailored by adjusting the width of slots 116. The desiredreduction in the circumference of the band is the total amount ofmaterial removed in the cutting process. For example, if a 0.254centimeter (0.100 inch) inner diameter is to be reduced to a 0.2032centimeter (0.080 inch) diameter, the circumference would need to bereduced from 0.7976 centimeter (0.314 inch), (π*0.254 centimeter), to0.6375 centimeter (0.251 inch), (π*0.2032 centimeters), or a reductionof 0.16 centimeter (0.063 inch). This could be achieved by 8 cuts of0.02032 centimeter (0.008 inch) width around the circumference of theband (a reduction of (0.1626 centimeter (0.064 inch)). Additionalgeometric parameters which could be varied, include, but are not limitedto, the length of the cuts, the number of the cuts, the overlap of thecuts, and the ratio of the long cuts to the short cuts. These parameterscould be varied to achieve desired force and deflection characteristics.Examples of outputs which could be changed are the ratio of the appliedballoon pressure to the sealing pressure, the ratio of diameterreduction to balloon volume, or the location of the virtual “pivotpoint” (or pivot region) of the band (114 in FIG. 1).

Said ring can be made from any resilient material with appropriatestiffness. Such materials include, but not limited to, nitinol, Titaniumalloys, Iron Alloys, and Cobalt Chromium alloys or polymers such asNylon, Polycarbonate, Polyester, Polyimide, Polyether block Amide, etc.Resilient materials allow ring member 100 to return back to its originalshape, or close to its original shape, when the force(s) which increasethe diameter of first end 102 is reduced.

In another embodiment, ring member 100 can be made from a plasticallydeformable material, such as a polymer or metal such as stainless steel.In this embodiment, when the radial force, which increases the diameterof first end 102, is reduced, ring member 100 will stay in the openposition (as illustrated in FIGS. 1C and 1D). This embodiment could beuseful for a permanent seal on an implantable occlusion balloon, forexample.

One use of the ring of the invention is that said ring can be used toseal at least one end of an inflatable member. One embodiment of theinvention is shown in FIGS. 2A through 2C as balloon catheter 201. Inthis embodiment, said ring of the invention (100) is used to seal atleast one end of an inflatable member on the distal end of a ballooncatheter. As illustrated in FIG. 2, the elongate member 203 has aproximal control end 207 and a distal functional end 209. The ballooncatheter also has a proximal guidewire lumen 211 that extends throughthe length of the elongate member 203 and exits the distal end at aguide wire port 213. Balloon catheter 201 is shown as an “Over The Wire”configuration, as commonly known in the art. As an alternate, thecatheter could have a mid-guidewire port and therefore have a “RapidExchange” configuration, as commonly known in the art.

The balloon catheter 201 also incorporates a proximal inflation port 215that allows fluid communication between the inflation port 215 and theinflatable member 205. The length and inner and outer diameter of theelongate member are selected based upon the desired application ofballoon catheter 201. For example, in one non-limiting embodiment,wherein balloon catheter 201 is used in percutaneous transluminalcoronary angioplasty, the length of the elongate member typically rangesfrom about 120 cm to about 140 cm. In this embodiment, the outerdiameter of the elongate member ranges from about 0.6 mm (about 0.024inches) to about 11.5 mm (about 0.45 inches). As will be understood bythe skilled artisan upon reading this disclosure, the length and/ordiameter of the elongate member are in no way limiting and may beroutinely modified for various applications of the medical devices ofthe present invention. The elongate member generally has a circularcross-sectional configuration.

Elongate member 203 must have sufficient structural integrity to permitthe medical device to be advanced to distal body conduit locationswithout bending or buckling upon insertion and have sufficient integrityto withstand a radial force from second end 104 of pivot ring member 100as the diameter decreases when the first end 102 of pivot ring 100 isshifting to an open configuration. Various techniques are known formanufacturing the tubular bodies. In one embodiment, the elongate memberis manufactured by extrusion of a biocompatible polymer.

As illustrated in FIGS. 2A and 2B, balloon catheter 201 comprises ringmember 100. Ring member 100 can be slid over inflatable member 205. Inthis embodiment, ring member 100 is placed at the proximal end ofinflatable member 205, with fingers 112 oriented toward the distal endof inflatable member 205 and ring members 118 oriented toward theproximal end of inflatable member 205. In another embodiment, ringmember 100 can be placed near the distal end of the balloon catheterwith fingers 112 oriented toward the proximal end of inflatable memberand ring members 118 oriented toward the distal end, as illustrated inFIG. 2D. Said ring member 100 can be slid over the inflatable member, asillustrated by arrow 225 in FIGS. 2A, 2B and 2E and 217 in FIGS. 2D and2E and placed anywhere along the length of inflatable member 205. FIG.2B depicts the same balloon catheter in FIG. 2A, except that ring member100 is moved axially toward the distal portion of inflatable member 205.Note that there is a relationship between inflation port(s) (see, 325 inFIG. 3A) and the pivot ring of the invention. A skilled artisan wouldunderstand where to position the pivot ring of the invention in relationto inflation port(s) on a catheter. In this embodiment, first end 102should be oriented to face the inflation port. In another embodiment,the inflation port can be at either end of the balloon or anywhere alongthe length of the balloon.

FIG. 2C depicts inflatable member 205 in an expanded configuration. Asinflatable member 205 expands, inflatable member forces first end 102 ofring member 100 to increase in diameter, as illustrated by arrows 223,and second end 104 decreases in diameter, as illustrated by arrows 221,which generates an inward force. As second end 104 decreases indiameter, it constricts against elongate member 203 and inflatablemember 205 resulting in a seal of at least one end of inflatable member205. Furthermore, said inward force also acts to embed the end of thering member into the balloon preventing axial movement. This seal can beplaced anywhere along the length of inflatable member 205, thus creatingan inflatable member that can be customized in length. Thus, anotherembodiment of the invention comprises using the ring of the invention toadjust the working length of an inflatable member.

As inflatable member 205 increases in diameter, the diameter of firstend 102 of ring member 100 also increases causing second end 104 tofurther decrease in diameter. The decrease in diameter causes sealingforce between inflatable member 205 and the elongate member 203 tobecome stronger. Thus, as the diameter of second end 104 of ring member100 becomes smaller, the seal between inflatable member 205 and elongatemember 203 becomes tighter. Ring member 100 creates a seal that isbeneficial in applications requiring higher inflation pressures.Compared to traditional seals requiring adhesives to prevent failure,this seal offers a mechanical action which acts to tighten withincreasing pressure. As the inflatable member inflates, the side of theband is lifted which pivots the opposite part of the band around afulcrum in the middle of the band. The pivoting causes the opposing partof the band to tighten around elongate member 203 allowing for ahigher-pressure seal. In one embodiment, more than one ring member 100can be placed in any orientation, moved, and placed in any area ofinflatable member 205 on catheter 201. As depicted in FIG. 2E, at least2 rings can be placed on an inflatable member. In this embodiment, thereis a proximal and distal seal as inflatable member 205 expands. Inanother embodiment, three, four, five or more pivot rings of theinvention can be placed on an inflatable member. Although the embodimentdepicted in FIG. 2 depicts a balloon catheter, any medical device withan inflatable member is also contemplated as part of this invention.Again, note that there is a relationship between inflation port(s) (see,325 in FIG. 3A) and the pivot rings of the invention. A skilled artisanunderstands that in the embodiment depicted in FIG. 2E, there needs tobe at least one inflation port between the rings.

Since the ring of the invention can be slid to any position along thelength (or along the axis) of an inflatable member (i.e. inflatableportion of inflatable member) the inflatable member can be customized insize (i.e. length) and/or working length.

As shown in FIG. 2, at least one inflatable element 205 is provided atthe distal end of the elongate member. An example of an inflatablemember useful in the present invention is a medical balloon. Other formsof inflatable elements include, but are not limited to balloon,expandable catheter, hoses, expandable pipes, and the like.

Thus, one embodiment of the invention comprises a medical devicecomprising, an inflatable member having opposing ends, a smallerdeflated profile and a larger inflated profile, a working length, and aring member having opposing ends, said ring member being slidable to anyposition between the opposing ends of the deflated inflatable member,wherein when one opposing end of said ring member increases in diameter,the other opposing end of said ring member decreases in diameter uponinflation of the inflatable member. In one embodiment, the increase inthe diameter of the ring member in one opposing end is driven by theinflatable member. In another embodiment, the decrease in diameter ofone of said opposing end of said ring member restricts inflation of aportion of said inflatable member. In another embodiment, saidinflatable member is disposed over an elongate member. In anotherembodiment, said elongate member is a catheter or a guidewire. Inanother embodiment, the decrease in diameter of the opposing end of saidring member makes said end constrict against said inflatable memberand/or said elongate member. In another embodiment, the constriction ofthe opposing end of said ring member against said inflatable memberand/or said elongate member result in a seal of at least one end of saidinflatable member. In another embodiment, as the diameter of theopposing end of said ring member decreases, the opposing end of saidring member further constricts against said inflatable member and/orsaid elongate member resulting in a tighter seal of at least one end ofsaid inflatable member. In another embodiment, the decrease in diameterof one of the opposing end of said ring member restricts axial movementof said ring member. In another embodiment, said inflatable member is amedical balloon. In another embodiment, said medical balloon comprisesexpanded polytetrafluoroethylene (ePTFE). In another embodiment, theposition of said ring member adjusts the working length of said medicalballoon. In another embodiment, said medical balloon further comprises aballoon cover. In another embodiment, said balloon cover comprisesePTFE. In another embodiment, said medical balloon comprises a drugcoating on said balloon and/or balloon cover. In another embodiment,said ring member comprises a resilient metal. In another embodiment,said resilient metal is nitinol. In another embodiment, the position ofsaid ring member adjusts the working length of the expandable portion ofsaid inflatable member.

In another embodiment, the invention comprises a medical devicecomprising an inflatable member having opposing ends, a smaller deflatedprofile and a larger inflated profile, a working length, and a ringmember having opposing ends, wherein said ring has a position betweenthe ends of the said inflatable member and wherein an increase indiameter on one of the opposing ends of said ring member results in acompressing force in the other opposing end of said ring member. In oneembodiment, the increase in the diameter of said ring member in oneopposing end is driven by said inflatable member. In another embodiment,said compressing force is caused by a decrease in diameter of one of theopposing ends of said ring member. In another embodiment, said decreasein diameter of one of said opposing ends of said ring member restrictsaxial movement of said ring member. In another embodiment, said decreasein diameter of one of said opposing ends of said ring member restrictsinflation of a portion of said inflatable member. In another embodiment,said inflatable member is disposed over an elongate member. In anotherembodiment, said elongate member is a catheter or a guidewire. Inanother embodiment, said compressive force causes said opposing end ofsaid ring member to constrict against said inflatable member and/or saidelongate member. In another embodiment, as the diameter of said opposingend of said ring member decreases, said opposing end of said ring memberfurther constricts against said inflatable member and/or said elongatemember resulting in a tighter seal of at least one end of saidinflatable member. In another embodiment, the inflatable member is amedical balloon. In another embodiment, said medical balloon comprisesePTFE. In another embodiment, the position of said ring member adjuststhe working length of said medical balloon. In another embodiment, saidmedical balloon further comprises a balloon cover. In anotherembodiment, said balloon cover comprises ePTFE. In another embodiment,said medical balloon comprises a drug coating on said balloon and/orballoon cover. In another embodiment, said ring member comprises aresilient metal. In another embodiment, said resilient metal is nitinol.

Another embodiment of the invention comprises a method of adjusting theworking length of an inflatable member comprising disposing at least onering member onto an inflatable member having a length, wherein said ringmember has opposing ends and when one opposing end of said ring memberincreases in diameter, the other opposing end of said ring memberdecreases in diameter upon inflation of the inflatable member, andsliding the at least one ring member to a predetermined position alongthe length of said inflation member. In one embodiment, increasing thediameter of one of the opposing ends of said at least one ring memberresults in a compressing force in the other opposing end of said ringmember. In another embodiment, the increase in the diameter of said oneopposing end of said at least one ring member is driven by saidinflatable member. In another embodiment, there are at least two ringmembers disposed on said inflatable member. In another embodiment, thedecrease in diameter of said one opposing end of said ring memberrestricts inflation of a portion of said inflatable member. In anotherembodiment, said inflatable member is disposed over an elongate member.In another embodiment, said elongate member is a catheter or aguidewire. In another embodiment, the decrease in diameter of theopposing end of said ring member makes said end constrict against theinflatable member and the elongate member. In another embodiment, theconstriction of the opposing end of said ring member against saidinflatable member and/or said elongate member results in a seal of atleast one end of said inflatable member. In another embodiment, as thediameter of the opposing end of said ring member decreases, saidopposing end of said ring member further constricts against saidinflatable member and/or said elongate member resulting in a tighterseal of at least one end of said inflatable member. In anotherembodiment, the decrease in diameter of one of said opposing end of saidring member restricts axial movement of said ring member. In anotherembodiment, said inflatable member is a medical balloon. In anotherembodiment, said medical balloon comprises ePTFE. In another embodiment,said medical balloon further comprises a balloon cover. In anotherembodiment, said balloon cover comprises ePTFE. In another embodiment,said medical balloon comprises a drug coating on said balloon and/orballoon cover. In another embodiment, said ring member comprises aresilient metal. In another embodiment, said resilient metal is nitinol.

In one embodiment, said inflatable member is a medical balloon. Inanother embodiment, said medical balloon has a concentric inflationmodality. The medical balloon according to the present invention may bemade using any materials known to those of skill in the art. Commonlyemployed materials include the thermoplastic elastomeric andnon-elastomeric polymers and the thermosets including the moistureand/or heat curable polymers. Examples of suitable materials include butare not limited to, polyolefins, polyesters, polyurethanes, polyamides,polyether block amides, polyimides, polycarbonates, polyphenylenesulfides, polyphenylene oxides, polyethers, silicones, polycarbonates,styrenic polymers, copolymers thereof, and mixtures thereof. Some ofthese classes are available both as thermosets and as thermoplasticpolymers. See, U.S. Pat. No. 5,500,181, for example. As used herein, theterm copolymer shall be used to refer to any polymeric material formedfrom more than one monomer.

In an alternative embodiment, as used herein, the term “copolymer” shallbe used to refer to any polymer formed from two or more monomers, e.g.2, 3, 4, 5 or more. Useful polyamides include, but are not limited to,nylon 12, nylon 11, nylon 9, nylon 6/9 and nylon 6/6. The use of suchmaterials is described in U.S. Pat. No. 4,906,244, for example.

Non-limiting examples of some copolymers of such materials include thepolyether-block-amides, available from Elf Atochem North America inPhiladelphia, Pa. under the tradename of PEBAX®. Another suitablecopolymer is a polyetheresteramide.

Suitable polyester copolymers, include, for example, polyethyeleneterephthalate (PET) and polybutylene terephthalate, polyester ethers andpolyester elastomer copolymers such as those available from DuPont inWilmington, Del. under the tradename of HYTREL®.

Block copolymer elastomers such as those copolymers having styrene endblocks, and midblocks formed from butadiene, isoprene,ethylene/butylene, ethylene/propene, and the like may also be employedherein. Other styrenic block copolymers include acrylonitrile-styreneand acrylonitrile-butadiene-styrene block copolymers. In an alternativeembodiment, it is possible to use in the present invention blockcopolymers wherein the particular block copolymer thermoplasticelastomers in which the block copolymer is made up of hard segments of apolyester or polyamide and soft segments of polyether.

Specific examples of polyester/polyether block copolymers arepoly(butylene terephthalate)-block-poly(tetramethylene oxide) polymerssuch as ARNITEL® EM 740, available from DSM Engineering Plastics andHYTREL® polymers available from DuPont de Nemours & Co, alreadymentioned above.

Suitable materials which can be employed in balloon formation arefurther described in, for example, U.S. Pat. No.s 6,406,457; 6,284,333;6,171,278; 6,146,356; 5,951,941; 5,830,182; 5,556,383; 5,447,497;5,403,340; 5,348,538; and 5,330,428.

The above materials are intended for illustrative purposes only, and notas limitations on the scope of the present invention. Suitable polymericmaterials available for use are vast and too numerous to be listedherein and are known to those of ordinary skill in the art.

Balloon formation may be carried out in any conventional manner usingknown extrusion, injection molding and other molding techniques.Typically, there are three major steps in the process which includeextruding a tubular preform, molding the balloon and annealing, orheating and cooling as appropriate for the particular material set(s),the balloon. Depending on the balloon material employed, the preform maybe axially stretched before it is blown. Techniques for balloonformation are described in U.S. Pat. No. 4,490,421, RE32,983, RE33,561and U.S. Pat. No. 5,348,538.

The inflatable member may be attached to an elongate member by variousbonding means known to the skilled artisan. Examples include, but arenot limited to, solvent bonding, thermal bonding, adhesive bonding, andheat shrinking or sealing. The selection of the bonding technique isdependent upon the materials from which the inflatable element andelongate member are prepared. Refer to U.S. Pat. No. 7,048,713, which isincorporated by reference herein in its entirety, for general teachingsrelating to the bonding of a balloon to a catheter.

In another embodiment, the balloon comprises expandedpolytetrafluoroethylene (ePTFE), as essentially taught in U.S. Pat. No.6,120,477 (Campbell, et al.), which is incorporated herein by referencefor all purposes. In another embodiment, the balloon, which can be madefrom any material described above or known in the art, is covered with aballoon cover, as essentially taught in U.S. Pat. No. 6,120,477(Campbell, et al.). In one embodiment said balloon cover comprise ePTFE.One important feature in selecting a material to make a balloon and/or aballoon cover is to allow the end of the ring member that is decreasingin diameter to embed into the material in order to get a tighter gripand/or a better seal. In one embodiment, said medical device comprises apolyurethane balloon comprising an ePTFE balloon cover and the ringmember of the invention. In one alternative embodiment, said medicaldevice comprises a PET balloon comprising an ePTFE balloon cover and thering member of the invention.

In another embodiment, the ring of the invention can be used to make asize adjustable single lumen high-pressure balloon catheter that sharesa guidewire lumen and an inflation lumen. This is significant because asingle lumen catheter has a smaller diameter (or French size), which isdesirable. The ring of the invention enables a size adjustablehigh-pressure balloon (about 10 atm to about 30 atm, depending ondiameter and length) to be mounted on a singe lumen catheter and toinflate said balloon to high pressures.

As depicted in FIGS. 3A and 3B, a single lumen high-pressure ballooncatheter can comprise a high-pressure balloon 305, lumen 311, at leastone inflation port 325, and pivot ring member 100 located near thedistal end of the outer wall of the catheter and/or on a portion of thehigh-pressure balloon. In another embodiment, said single lumenhigh-pressure balloon catheter also comprises a sealing agent 330located toward the distal end of the inner wall of the catheter. Saidhigh-pressure balloon can be mounted on the catheter by methodsdescribed above and/or known in the art.

When a guidewire 340 (or other tubular device such, as a catheter) isadvanced into lumen 311 and to, or past, distal port 313 it occludesdistal port 313. When inflation media is added from the proximal end(e.g. see, 215 in FIG. 2) there will be no, or minimal, leaking of theinflation media from distal port 313 thus allowing the balloon toinflate through the inflation port(s) 325. As more inflation media isadded, the media will flow through the inflation port(s) 325 and intoballoon 305 thereby increasing the pressure within the system andcausing balloon 305 to inflate. As balloon 305 inflates, as depicted inFIG. 3B, ring member 100 will begin to increase in diameter at first end102 and decrease in diameter at the second end 104 (as described above).As second end 104 decreases in diameter, it generates an inward force,depicted by arrows 329, which compresses distal port 313 (or a specificarea of the catheter) and optional sealing agent 330 around guidewire340 (or other tubular structure). As the pressure inside the balloonincreases, thus decreasing the diameter of second end 104, the strongerthe compressive force becomes at distal end 313 and the tighter the sealbetween the guidewire 340, distal end 313, and optional sealing agent330. In this embodiment, there will be no, or minimal, inflation medialeakage as the balloon is inflating to its final pressure. Without ringmember 100, distal port 313 will begin to leak at a lower pressure,making it unsuitable for applications such as balloon angioplasty. Thissystem allows for having a high-pressure balloon using a single lumencatheter. In one embodiment, said high-pressure balloon comprises aballoon with about an 8 mm expanded diameter that can be inflated to apressure up to about 14 atm. In another embodiment, said sealing agentis selected from the group consisting of silicone, urethane,fluoroplastics, or polyether block amide. In another embodiment, saidother tubular structure is a catheter, guidewire or hypotube. In anotherembodiment, said single lumen high-pressure balloon catheter comprisesat least two pivoting ring members of the invention, as depicted in FIG.2E.

In another embodiment, there is a small gap between the distal port 313and guidewire 340 (or other tubular structure). The small gap allowsguide wire 340 (or other tubular structure) to slide smoothly throughdistal end of the catheter, including distal port 313. As inflationmedia is added into lumen 311, a small of amount of leaking can occur,however as balloon 305 inflates, ring member 100 will increase indiameter at first end 102 and decrease in diameter at the second end 104(as described above). As second end 104 decreases in diameter, itgenerates an inward force, depicted by arrows 329, which compresses thedistal end of the catheter, including distal port 313 around guidewire340 (or other tubular structure). As the pressure inside the balloonincreases, thus decreasing the diameter of second end 104, the strongerthe compressive force becomes at distal end of the catheter and thetighter the seal between the guidewire 340 and distal end of thecatheter, including distal port 313. In another embodiment, the cathetercomprises sealing agent 330 located toward the distal end of the innerwall of the catheter.

Medical devices of the present invention are useful in treating sites ina body conduit or delivering interventional devices as described above.In one embodiment, the medical device of the present invention is usedin angioplasty procedures. In this method, the medical device of thepresent invention is placed percutaneously and advanced so that theinflatable member, in a smaller diameter profile, is adjacent to avascular treatment site. In one embodiment, said one or more rings ofthe invention can be adjusted prior to insertion in the body and/or insitu when said inflatable member is adjacent to vascular treatment site.Generally, the treatment site is a stenosis caused, for example, byplaque or a thrombus. The inflatable member of the medical device isthen inflated at a pressure or force sufficient to inflate theinflatable member. After the stenosis is compressed to or beyond thenative diameter of the lumen, the inflatable element is evacuated andthe medical device is withdrawn from the body lumen. In anotherembodiment, said medical devices of the present invention are useful fordelivering an interventional device to a treatment site. In anotherembodiment, the working length of the inflatable member is customized tothe length of the stenosis to be treated and/or to the length of aninterventional device. As used herein, “body conduit” comprises anartery, vein and/or other lumen.

Another embodiment of the invention comprises a method of treating asite in a body conduit with a medical device as described herein, saidmethod comprising the steps of determining the appropriate length of theinflatable member required, moving the ring of the invention along thelength of the inflatable member to the appropriate location of theinflatable member, positioning within a body conduit the medical deviceof the invention so that the inflatable element is in a non-inflated(such as in a folded or comparable configuration) form is adjacent to atreatment site; and inflating the inflatable element at a pressure orforce sufficient to inflate the inflatable element. The steps ofdetermining the appropriate length of the inflatable member and movingthe ring of the invention along the length of the inflatable member tothe appropriate location may be carried out either prior to positioningthe medical device in the body conduit or in situ once the medicaldevice is placed in the body conduit, or some combination thereof. Inone embodiment, said inflatable element expands an interventionaldevice. In another embodiment, said interventional device is a stent. Inanother embodiment, said interventional device is a stent-graft. Inanother embodiment, said stent comprises nitinol and/or stainless steel,as commonly known in the art. In another embodiment, said treatment siteis an artery, vein and/or other lumen within a body.

Another embodiment of the invention comprises creating a customizablestent length and customizing the length of the delivery balloon. Forexample, as disclosed in U.S. Patent Application Publication U.S.2009/0182413 (which is incorporated by reference herein for allpurposes), the stent with polymer interconnecting webs can be cut to apreferred size by medical staff prior to insertion in the body. Byproviding at least one ring of the invention in combination with anysize balloon, the working length of the balloon can be adjusted to thelength of the stent. In another embodiment, said customizable stentcomprises stent rings interconnected by a graft, tube, film, polymerlinks and/or any material known in the art, such as ePTFE.

Thus, another embodiment of the invention comprises a medical stentingsystem comprising a medical balloon having opposing ends, a smallerdeflated profile and a larger inflated profile, and a working length, atleast one ring member having opposing ends, wherein an increase indiameter of one of the opposing ends of said ring member results in acompressing force in the other opposing end of said ring member, whereinsaid ring member has a position between the opposing ends of saidinflatable member, and a customizable stent that can be adjusted to apredetermined length. In one embodiment, the position of said ringadjusts the working length of said medical balloon. In anotherembodiment, said stent is disposed over the working length of saidmedical balloon. In another embodiment, said medical balloon is disposedover an elongate member. In another embodiment, said elongate member isa catheter. In another embodiment, said customizable stent comprisesstent rings interconnected by polymer webs. In another embodiment, saidcustomizable stent is customized by cutting said polymer webs andremoving stent rings. In another embodiment, said medical ballooncomprises ePTFE. In another embodiment, said medical balloon furthercomprises a balloon cover. In another embodiment, said medical ballooncover comprises ePTFE. In another embodiment, said medical ballooncomprises a drug coating on said balloon and/or balloon cover. Inanother embodiment, said ring member comprises a resilient metal. Inanother embodiment, said resilient metal is nitinol.

In another embodiment, the invention also comprises a method ofintroducing a customizable stent into a body conduit comprising,providing a customizable stent and a medical balloon having opposingends, a smaller deflated profile and a larger inflated profile, and aworking length, adjusting said customizable stent to a predeterminedlength, adjusting said working length of said medical balloon bydisposing and sliding at least one ring member between said opposingends of said medical balloon, wherein said ring member comprisesopposing ends and an increase in diameter on one of the opposing ends ofsaid ring member results in a compressing force in the other opposingend of said ring member, disposing said stent onto the working length ofthe medical balloon, and inserting said medical balloon, at least onering member and stent into a body conduit. In one embodiment, saidmedical balloon and said stent is delivered to a predetermined sitewithin said body conduit and said working length of said medical balloonis expanded thereby delivering said stent disposed on said balloon. Inanother embodiment, said customizable stent comprises stent ringsinterconnected by polymer webs. In another embodiment, said customizablestent is customized by cutting said polymer webs interconnecting saidstent rings and removing said stent rings. In another embodiment, saidmethod comprises at least two ring members and sliding said ring membersadjusts the working length of said medical balloon. In anotherembodiment, said medical balloon is disposed over an elongate member. Inanother embodiment, said elongate member is a catheter. In anotherembodiment, said medical balloon comprises ePTFE. In another embodiment,said medical balloon further comprises a balloon cover. In anotherembodiment, said balloon cover comprises ePTFE. In another embodiment,said medical balloon comprises a drug coating on said balloon and/orballoon cover. In another embodiment, said ring member comprises aresilient metal. In another embodiment, resilient metal is nitinol.

Another embodiment of the invention comprises placing the at least onering of the invention over a balloon used to deliver drugs. Drug elutingballoons may comprise a coating of a drug on the balloon and/or onanother surface adjacent to the balloon which is designed to elute onlywhen the balloon is expanded. In another embodiment, said drug elutingballoon can weep and/or deliver a drug though the surface of the balloonand/or balloon cover. The use of at least one ring of the invention candetermine the area of the drug eluting balloon that can be expanded andthus determine the amount of drug and/or pinpoint the area and/orcontrol the dose of drug delivered to a body conduit. Thus, drug elutioncan be controlled by adjusting the working length of the balloon bymoving the ring(s) of the invention to the desired location of a drugeluting balloon. In one embodiment, said drug eluting balloon hasmultiple drugs along the length of said balloon which can be deliveredby moving said pivot ring(s) of the invention along the length of thedrug eluting balloon. In addition, said expansion of the balloon can becontrolled by moving multiple rings to specific areas of the balloon incoordination with inflation ports. In another embodiment, said drug isplaced on only a portion of a balloon, for example on the proximal end.In this embodiment, the ring(s) can be moved to only inflate the portionof the balloon without drug, thereby expanding a body conduit. Then thepivot ring(s) of the invention can be moved, in situ, toward the distalend to expand the portion of the balloon with a drug, to deliver thedrug to the expanded body conduit. This system allows for body conduitexpansion, without drug delivery, and then delivering a drug to theexpanded body conduit without having to remove the balloon and insertinganother. In another embodiment, said drug is selected from the groupconsisting of paclitaxel, dexamethasone, rapamycin, any analoguesthereof, and any combination thereof.

In another embodiment, the pivot ring of the invention can be used todeliver multiple drug treatments per balloon catheter. In oneembodiment, for example, a balloon catheter with a 100 mm drug treatmentsection can be delivered to the desired treatment site where the pivotring of the invention is positioned to only allow expansion at thedistal 40 mm of said balloon. The pivot ring of the invention (ormultiple pivot rings) can then be repositioned either in situ, or uponremoval and manually repositioning of the said pivot ring(s), for asubsequent inflation of a previously un-expanded balloon section todeliver another drug or same drug associated with that previouslyun-expanded section of the balloon. This embodiment would allow formultiple drug deliveries per balloon catheter, each with a customizabletreatment length.

Several embodiments of the instant invention allows for repositioning ofsaid pivot ring(s) in situ. In one embodiment, the pivot ring of thepresent invention can be fixedly attached to a control means whichextends to the proximal portion of the catheter allowing the clinicianto adjust the position of the band along the inflatable member while theinflatable member remains in the body. In another embodiment, thecontrol means can be a thin wall tube sized appropriately to fit overthe outer diameter (OD) of the pivot ring of the invention and allowingit to be attached at a point in the band which includes the fulcrum ofthe pivot in the band. In this embodiment, the control tubing couldextend the full length of the catheter proximally, to a point in acontrol handle where medical staff could pull on the tubing toreposition the band. In another embodiment, the thin wall tube could bea PTFE tube comprising a thermoplastic FEP. This tube could be heatedwhen positioned over the band to allow the FEP to reflow and bond to theband. In another embodiment, a fiber is fixedly attached to a feature onthe band. The catheter, which holds the expandable member, could includea lumen for the fiber which extends to the proximal end of the catheter.The fiber could exit the lumen at a point either distal or proximal tothe band, allowing the band to be repositioned in either directionaxially along the inflatable member to either lengthen or shorten theworking length of the inflatable member in situ. In another embodiment,multiple means for repositioning the band can be employed on a singleband to allow the band to be repositioned more distally or moreproximally, multiple times throughout a procedure. In anotherembodiment, the control tube could have enough column and tensilestrength to allow the band to repositioned in either direction along theaxial length of the inflatable member. Thus, one embodiment of theinvention comprises, adjusting said working length of a balloon in situ,while the balloon is in a patient by, for example, attaching a wire,tube and/or fiber to the pivot ring(s) and running said wire, tubeand/or fiber to the proximal end of the catheter for medical staff tomanipulate. In another embodiment, medical staff determines the workinglength of the balloon by moving the ring to the desired location alongthe length of the balloon to determine the working length of the balloonbefore placing the balloon into the body conduit of a patient.

Another embodiment of the invention comprises controlling the diameterof the balloon by pulling stored length out of the working length of theballoon under the ring members 118 such that when said opposing secondend 104 of said ring member decreases in diameter upon inflation of theinflatable member, the stored length will be outside second end 104(opposite first end 102) and not allowed to slip under the ring, thuscontrolling the diameter of the balloon. This would be useful inembodiments that involve inflatable members which incorporate a materialset that foreshortens during inflation, thus requiring the storage ofexcess length to allow inflation to a preset diameter. These materialsmay comprise films, braids, knits, etc., and may comprise expanded PTFEor other suitable material compositions. Thus, in one embodiment, thering of the invention can determine the working length and diameter of aballoon.

Another embodiment of the invention comprises a device and methodwhereby the ring of the invention can re-compact, or refold, a balloonafter inflation. One of the problems with a non-compliant balloon isthat when the balloon is inflated and deflated, the balloon does not goback to its original folded shape and creates flaps and/or wings thatresult in a larger balloon profile which cannot be easily removed fromthe patient and/or retracted into a sheath. In other words, the balloonis difficult to remove, because the material does not compact easily.Thus, one embodiment of the invention comprises configuring the fingersof the ring of the invention to be long enough to extend at leastpartially up to the cone of the balloon so that after deflation of theballoon, the ring pivots back to its original shape and the fingers(112, FIG. 4) help in the refolding or recompaction of the balloon. Asdepicted in FIG. 4A, when balloon 405 is inflated, rings 100 at firstend 102 expands and second end 104 reduces in diameter. Fingers 112spread as first end 102 expands. When the balloon is deflated, the firstend 102 will begin to reduce in diameter and fingers 112 will start tocome together and create folding creases 422 in balloon 405. Thesefolding creases will help balloon 405 fold. As shown in FIG. 4B, theballoon is re-compacted due to the folding creases 422 created byfingers 112. FIG. 4C is an end view of balloon 405 and ring member 100as it is being deflated. As shown, finger 112 creates folding creases tohelp the balloon fold into a more compacted state. Thus, it allows fortighter compaction of the balloon. In one embodiment, the fingers arealigned with the folds of the balloon so that when the balloon deflates,the fingers allow for refolding. In another embodiment, the balloon onlyincludes one pivot ring that is placed toward the proximal end of aballoon, the end which will first enter a sheath upon withdrawal.

In another embodiment of the invention, a method comprises controllingthe flow of a vascular graft in situ. One embodiment of the inventioncomprises placing the ring of the invention on a vascular graft, forexample on GORE-TEX Vascular Graft (item no. V03050L, W. L. Gore andAssociates, Inc., Flagstaff Ariz.), and implanting said graft in apatient. The ring may be configured to change shape due to a variety ofconditions which may be imposed on the patient, the device or somecombination of the two. In one embodiment, the ring of the inventionmade so that it is sensitive to temperature such that at bodytemperature, the ring of the invention is in the open position (see,FIGS. 1C and 1D) and when it is at a lower temperature the ring is inthe closed position (see, FIGS. 1A and 1B). The open and closedpositions of the ring of the invention can be accomplished by shapesetting the ring of the invention at different temperatures by usingmemory alloys, like nitinol, as commonly known in the art. Thus, whenthe graft comprising the ring of the invention is placed in a patient,e.g. as an arteriovenous (AV) fistula, the ring is in the open position,not allowing blood flow, or reducing the amount of blood flow. During adialysis procedure, the temperature of the ring can be lowered, e.g. byplacing a bag of ice on the patient's arm to cool the ring on the AVgraft, thus allowing the ring to adjust to an closed position andallowing increased blood flow. Thus, when the vascular graft is not inuse for a dialyses procedure, the blood flow is reduced and wouldprevent or diminish outflow stenosis, which is a common occurrence withan AV graft.

Although the invention described supra mainly discussed the use of thering of the invention for medical applications, this ring can be usedfor non-medical application. For example, the ring of the invention canbe used to control the flow of a liquid in tube, e.g. a garden hose orother tube. When the tube dilates, the flow can be restricted and/orclosed altogether. For example, a hose connection that allow for easyslip fit connection, but that tightens/seals when water is turned on andremovable when water is turned off.

While particular embodiments of the present invention have beenillustrated and described herein, the present invention should not belimited to such illustrations and descriptions. It should be apparentthat changes and modifications may be incorporated and embodied as partof the present invention within the scope of the following claims. Thefollowing examples are further offered to illustrate the presentinvention.

EXAMPLES Example 1 Constructing Pivot Ring

A pivot ring was made by cutting the pattern illustrated in FIG. 5 intoa nitinol tube with an outside diameter of 0.086″ and inside diameter of0.074″. For ease of illustration, FIG. 5 depicts the flat pattern thatwas cut into the tube. The cut pattern provided for 8 slots in clampingside 504 of the ring with widths of 0.004″ each. Fully closed, thiswould result in roughly a 0.064″ diameter or a 0.010″ reduction ininside diameter. The cut utilized a staggered orientation of openingslits 502 and clamping slots with roughly a 2:1 length ratio (openingfinger length:closing finger length). FIG. 5B is shown as tubulardepiction of the resulting band.

Example 2 Constructing a Balloon Catheter

EPTFE balloon construct was made according to the teachings of U.S. Pat.No. 6,923,827, Campbell, et al. Forty layers of ePTFE were wrappedaround a 6 mm mandrel at a high angle and in opposing directions. Thistube was heated at 380° C. for approximately 8 minutes to fuse thelayers together. The tube was removed from the mandrel and stretchedwhich resulted in a reduction in inside diameter to at least below0.075″. The tubing was then slid onto a 0.075″ stainless steel mandrel.A sacrificial overwrap of ePTFE film was placed over the tubing and itslength was evenly reduced to 60% of its original length. The tube washeated at 380° C. for one minute and the sacrificial ePTFE was removed.This ePTFE tube was dipped into a 12% solution of Biospan polyurethane(DSM, Netherlands) in DMAC (N,N Dimethylacetamide). Three dips were madeinto the solution with a heat/drying step between each step to dry offthe solvent. This tube was removed from the mandrel and inverted suchthat the polyurethane was on the inside diameter and the length wastrimmed to approximately 60 mm (ePTFE balloon construct). A 0.063″ outerdiameter Nylon tube with an inner diameter of approximately 0.053″ wasprepared to allow for inflation. The distal end of the tube was occludedto prevent passage of inflation media. Inflation ports were skived intothe side of the tube at the distal end to allow for easy passage ofinflation media. A single luer fitting was fixedly attached to theproximal end of the tube with UV curing Dymax 208CTH.

The previously created ePTFE balloon construct was then placed over thedistal end of the Nylon tube. The balloon construct was positioned suchthat the inflation ports were located just distal of the proximal edgeof the balloon. ePTFE film with applied Loctite 4981 was wrapped aroundthe proximal edge of the ePTFE balloon construct to seal the balloon tothe nylon tube and prevent the passage of inflation media. The ring ofExample 1 was then placed onto the balloon construct from the unsealeddistal end in an orientation with clamping side 504 of the ring facingdistally and opening side 502 of the ring facing proximally, towards theinflation ports (see, FIGS. 6 and 7). Expanded PTFE film with appliedLoctite 4981 was wrapped around the distal edge of the balloon constructto seal the balloon to the nylon shaft and prevent the passage ofinflation media.

Example 3 Illustration of Pivot Ring on a Balloon Catheter

The catheter construct of Example 2 was inflated to 6 atm's with theband in a location approximately 28 mm from the proximal seal (FIG. 6A).This resulted in a total inflated length of roughly 28 mm and noinflation media was observed passing underneath the pivoting ringmember. The balloon was deflated (FIG. 6B) and the ring was repositioneddistally about 10 mm (as depicted by arrow 615 in FIG. 6C). The balloonwas reinflated to 8 atm's and the new inflated length of the balloon wasabout 38 mm (FIG. 6D) and again, no inflation media was observed passingunderneath the pivoting ring. A closer image of the pivot band in itspivoted state (FIG. 7, with reference numbers as described in FIG. 1) isshown to demonstrate the band embedding into the balloon construct tomake a seal and prevent axial migration upon inflation.

Numerous characteristics and advantages of the present invention havebeen set forth in the preceding description, including preferred andalternate embodiments together with details of the structure andfunction of the invention. The disclosure is intended as illustrativeonly and as such is not intended to be exhaustive. It will be evident tothose skilled in the art that various modifications may be made,especially in matters of structure, materials, elements, components,shape, size and arrangement of parts within the principals of theinvention, to the full extent indicated by the broad, general meaning ofthe terms in which the appended claims are expressed. To the extent thatthese various modifications do not depart from the spirit and scope ofthe appended claims, they are intended to be encompassed therein. Inaddition to being directed to the embodiments described above andclaimed below, the present invention is further directed to embodimentshaving different combinations of the features described above andclaimed below. As such, the invention is also directed to otherembodiments having any other possible combination of the dependentfeatures claimed below.

What is claimed is:
 1. A medical device comprising: an inflatable memberhaving opposing ends, a smaller deflated profile and a larger inflatedprofile, and a working length; and a ring member having opposing ends,said ring member being slidable to a range of positions between theopposing ends of the deflated inflatable member, wherein when oneopposing end of said ring member increases in diameter, the otheropposing end of said ring member decreases in diameter upon inflation ofthe inflatable member; wherein the decrease in diameter of said oneopposing end of said ring member restricts inflation of a portion ofsaid inflatable member.
 2. The medical device of claim 1, wherein theincrease in the diameter of the ring member in one opposing end isdriven by the inflatable member.
 3. The medical device of claim 1,wherein said inflatable member is disposed over an elongate member. 4.The medical device of claim 3, wherein said elongate member is acatheter or a guidewire.
 5. The medical device of claim 3, wherein thedecrease in diameter of the opposing end of said ring member makes saidopposing end constrict against said elongate member.
 6. The medicaldevice of claim 5, wherein the constriction of the opposing end of saidring member against said elongate member result in a seal of at leastone end of said inflatable member.
 7. The medical device of claim 6,wherein as the diameter of the opposing end of said ring memberdecreases, the opposing end of said ring member further constrictsagainst said elongate member resulting in a tighter seal of at least oneend of said inflatable member.
 8. The medical device of claim 1, whereinthe decrease in diameter of one of the opposing end of said ring memberrestricts axial movement of said ring member.
 9. The medical device ofclaim 1, wherein said inflatable member is a medical balloon.
 10. Themedical device of claim 9, wherein said medical balloon comprises ePTFE.11. The medical device of claim 9, wherein the position of said ringmember adjusts the working length of said medical balloon.
 12. Themedical device of claim 9, wherein said medical balloon furthercomprises a balloon cover.
 13. The medical device of claim 12, whereinsaid balloon cover comprises ePTFE.
 14. The medical device of claim 9,wherein said medical balloon comprises a drug coating.
 15. The medicaldevice of claim 1, wherein said ring member comprises a resilient metal.16. The medical device of claim 15, wherein said resilient metal isnitinol.
 17. The medical device of claim 1, wherein the position of saidring member adjusts the working length of said inflatable member.
 18. Amedical device comprising: an inflatable member having opposing ends, asmaller deflated profile and a larger inflated profile, and a workinglength; and a ring member having opposing ends, wherein said ring memberhas a position between the opposing ends of the said inflatable memberand wherein an increase in diameter on one of the opposing ends of saidring member results in a compressive force in the other opposing end ofsaid ring member; wherein said compressive force of said one opposingend of said ring member restricts inflation of a portion of saidinflatable member.
 19. The medical device of claim 18, wherein theincrease in the diameter of said ring member in one opposing end isdriven by said inflatable member.
 20. The medical device of claim 18,wherein said compressive force is caused by an increase in diameter ofone of the opposing end of said ring member.
 21. The medical device ofclaim 18, wherein said compressive force of one of said opposing end ofsaid ring member restricts axial movement of said ring member.
 22. Themedical device of claim 18, wherein said inflatable member is disposedover an elongate member.
 23. The medical device of claim 22, whereinsaid elongate member is a catheter or a guidewire.
 24. The medicaldevice of claim 22, wherein said compressive force causes said opposingend of said ring memer to constrict against said elongate member. 25.The medical device of claim 24, wherein as the diameter of said opposingend of said ring member decreases, said opposing end of said ring memberfurther constricts against said elongate member resulting in a tighterseal of at least one end of said inflatable member.
 26. The medicaldevice of claim 18, wherein the inflatable member is a medical balloon.27. The medical device of claim 26, wherein said medical ballooncomprises ePTFE.
 28. The medical device of claim 26, wherein theposition of said ring member adjusts the working length of said medicalballoon.
 29. The medical device of claim 26, wherein said medicalballoon further comprises a balloon cover.
 30. The medical device ofclaim 29, wherein said balloon cover comprises ePTFE.
 31. The medicaldevice of claim 26, wherein said medical balloon comprises a drugcoating.
 32. The medical device of claim 18, wherein said ring membercomprises a resilient metal.
 33. The medical device of claim 32, whereinsaid resilient metal is nitinol.
 34. A method of adjusting a workinglength of an inflatable member comprising: disposing at least one ringmember onto an inflatable member having a length, wherein said at leastone ring member has opposing ends and when one opposing end of said atleast one ring member increases in diameter, the other opposing end ofsaid at least one ring member decreases in diameter upon inflation ofthe inflatable member; and sliding the at least one a ring member to apredetermined position along the length of said inflatable member,wherein increasing the diameter of said one opposing ends of said atleast one ring member results in a compressing force in the other posingend of said ring member.
 35. The method of claim 34, wherein theincrease in the diameter of said one opposing end of said at least onering member is driven by said inflatable member.
 36. The method of claim34, wherein there are two ring members disposed on said inflatablemember.
 37. The method of claim 34, wherein the decrease in diameter ofsaid one opposing end of said at least one ring member restrictsinflation of a portion of said inflatable member.
 38. The method ofclaim 34, wherein said inflatable member is disposed over an elongatemember.
 39. The method of claim 38, wherein said elongate member is acatheter or a guidewire.
 40. The method of claim 38, wherein thedecrease in diameter of the opposing end of said at least one ringmember makes said opposing end constrict against the inflatable memberand the elongate member.
 41. The method of claim 40, wherein theconstriction of the opposing end of said at least one ring memberagainst said elongate member result in a seal of at least one end ofsaid inflatable member.
 42. The method of claim 38, wherein as thediameter of the opposing end of said at least one ring member decreases,said opposing end of said ring member further constricts against saidelongate member resulting in a tighter seal of at least one end of saidinflatable member.
 43. The method of claim 34, wherein the decrease indiameter of one of said opposing end of said ring member restricts axialmovement of said ring member.
 44. The method of claim 34, wherein saidinflatable member is a medical balloon.
 45. The method of claim 44,wherein said medical balloon comprises ePTFE.
 46. The method of claim44, wherein said medical balloon further comprises a balloon cover. 47.The method of claim 46, wherein said balloon cover comprises ePTFE. 48.The method of claim 44, wherein said medical balloon comprises a drugcoating.
 49. The method of claim 34, wherein said at least one ringmember comprises a resilient metal.
 50. The method of claim 49, whereinsaid resilient metal is nitinol.